JPH0470275A - Digital still camera - Google Patents

Abstract

PURPOSE:To properly use photographing modes, and to optimize photographing by making a normal photographing mode and a high resolution mode switchable. CONSTITUTION:In a digital still camera which executes prescribed exposure by a solid state image pickup element 28 in the normal photographing mode, the normal photographing mode and the high resolution mode are made switchable. Then, a shifting member 29 which shifts the solid state image pickup element 28 in parallel by the portion of half picture element pitch at the time of the high resolution mode and an exposure control means which executes the prescribed exposure before and after the displacement of the solid state image pickup element 28 respectively at the time of the photographing in the high resolution mode are provided. Then, at the time of the normal photographing mode, the prescribed exposure is executed only once by the solid state image pickup element, and at the time of the high resolution mode, the solid state image pickup element is shifted by the portion of half picture element pitch, and the prescribed exposure is executed once each time before and after this displacement.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a digital device that enables high-resolution photography by displacing a solid-state element by a predetermined amount and performing two exposures before and after the displacement. Regarding still cameras.

[Conventional technology]

Conventionally, CO used in television cameras, still cameras, etc.
For DII elements, various methods have been proposed to improve the substantial resolution without increasing the physical size by relatively displacing the CCDI image element and the subject image vertically or horizontally.

For example, in Japanese Patent Application Laid-open No. 58-197970, IIIl
A device that uses a piezoelectric element such as an image debug device T or an electromagnetic transducer such as a linear motor to cause displacement in the vertical or horizontal direction has been proposed.

Furthermore, in Japanese Patent Application Laid-Open No. 59-22485, a support plate on which a solid-state image sensor is fixed is sandwiched between two leaf springs protruding from a base, and a piezoelectric element is used to move the support plate in parallel. An arrangement in which the image sensor is displaced is shown.

In addition, Japanese Patent Application Laid-Open No. 64-60072 discloses that a bimorph piezoelectric element is used to move a parallel plate in parallel to obtain a C of an object image.
An arrangement is shown in which the image formation position on the OD element is displaced by 1/2 pixel pitch.

[Problem to be solved by the invention]

By the way, in all of the conventional photographing methods described above, the light utilization efficiency of the solid-state image sensor is improved by displacing the solid-state image sensor by a predetermined amount in one photographing operation and performing predetermined exposures before and after the displacement. , ^ This is intended to improve resolution.

However, the conventional photographing method described above has the disadvantage that the release time lag is longer than in a normal photographing operation because two exposures are performed in one photographing operation. It is desirable to be able to select an appropriate imaging method for cases in which priority is given to a short time lag over high resolution, and in cases in which priority is given to high resolution even with a long time lag.

The present invention has been made in view of the above-mentioned problems, and enables switching between a normal shadow mode and a high-resolution mode in which a solid-state image sensor is displaced and exposure is performed twice before and after the displacement, thereby allowing suitable photographing. The purpose of the present invention is to provide a digital still camera that can perform

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a digital still camera that performs a predetermined exposure using a solid-state image pickup device in a normal shooting mode, which switches between the normal shooting mode and a high resolution mode. a switching means, a displacement means for parallelly moving the solid-state image sensor by 1/2 pixel pitch when in the high-resolution mode, and a predetermined exposure before and after the displacement of the solid-state image sensor when shooting in the high-resolution mode. and an exposure control means for controlling the exposure.

C Effect] In the digital still camera configured as described above, in the normal shooting mode, the solid-state image sensor performs a predetermined exposure only once. Also, in high resolution mode,
The solid-state image sensor is displaced by 1/2 pixel pitch, and the predetermined exposure is performed once before and after the displacement.

[Embodiment] FIG. 3 is a front view showing an embodiment of a digital still camera according to the present invention. In addition, Figures 4 and 5 are
FIG. 2 is a plan view and a side view of the digital still camera, respectively. In Fig. 3, 1 is the camera body, 2 is the release button, and 3 is the light receiver N (for auto white balance).
AW8! , 4 is a see-through type finder, 5 is a flash emission window, 6 is a photographing lens, and 7 is a lamp projection window. Further, 8 is a light receiving window for photometry, and 9 is a photographing mode changeover switch. The photographing mode changeover switch 9 also serves as a power switch, and when set to rOFFJ, power supply is stopped. In addition, the shooting mode can be switched between a normal shooting mode for shooting natural images such as people and landscapes, and a text shooting mode for close-up shooting of letters, figures, etc. In the rNORM and J positions, the normal shooting mode is set. is selected, and in the CHARACT and J positions, the character shooting mode is selected. Also, 10 is a changeover switch for changing the shooting magnification, and the switch 10 selectively switches the IIl magnification between standard shooting and macro shooting. Standard photography is selected in the rNORM and J positions, and macro photography is selected in the rcLO8E UPJ position.Furthermore, 11 is an operation button for switching the flash emission mode, and the emission mode switching button 1
By pressing 1, two types of light emission modes, strong 11J light emission and light emission prohibition, can be selected. Further, 12 is an eject switch for an IC card which is a recording medium for image data, and when the switch 12 is slid to the rEJECTJ side, the IC card inserted into the insertion slot 15 (see Fig. 5) is ejected. be done.

Further, in FIG. 4, numeral 13 is a display section consisting of an LCD, LED, etc., for displaying data such as the number of shots, the shooting mode, exposure control l111[, shooting date, etc.], and 14 is an operation button for setting the date. . Also, in Figure 8,
15 is an insertion slot for an IC card, and 16 is a lid for a battery mounting section.

Next, FIG. 1 is a system configuration diagram of the digital still camera.

In the figure, 17 is a central control unit (hereinafter referred to as CPU) that centrally controls the operation of the entire camera, and 18 is a power supply circuit that supplies *** to each circuit to be described. Also, 1
Reference numeral 9 denotes a distance measuring circuit that calculates the amount of day focus from the current position of the lens to the unmarked position of the main subject. In this distance measuring circuit 19, the absolute distance to the main subject is also calculated, and the CP
U17 with main subject distance and built-in flash guide number.

From No., the appropriate exposure for so-called flashmatic is calculated. Further, 20 is a photometry circuit that measures the subject brightness, 21 is a flash circuit that controls flash emission and charging of a flash emission capacitor, 22 is a display circuit that displays various data on the display section 13, and 2
3 is an auto white balance (AWB) circuit that measures the color temperature of the subject; 24 is a lamp projection circuit that illuminates the subject when photographing characters; and 25 is a circuit that illuminates the photographic lens 6 during exposure. A mirror is a mirror that guides the transmitted light to the image sensor, blocks light from the image sensor except during exposure, and guides the transmitted light to the photometry circuit 20. Also, 26 is a mechanical shutter that controls exposure. As shown in Fig. 12, the amount of closing of the shutter curtain 26a can be monitored by detecting the hole 65 provided in one shutter curtain 26a with a photointerrupter 67. That is, the shutter 126a rotates clockwise from the fully open state. However, when the aperture 66 is closed as shown by the virtual line, a pulse that detects the hole 65 is output from the photointerrupter 67, and by counting the number of pulses, the amount of rotation of the shutter curtain 26a is detected. 2
Since the amount of rotation of 6a corresponds to the amount of closing of the aperture 66 by the shutter curtains 26a and 26b, the corresponding amount of interleaving of the aperture t-66 can be detected from the amount of rotation.

Returning to FIG. 1, 27 is a motor drive circuit that controls the drive of the motor M. The motor M moves the mirror 25, exposes the shutter 26 to 1%, and controls the photographing lens 6.
This is a drive source for focusing, switching magnification, etc.

Further, 28 is a solid-state image sensor (hereinafter referred to as COD), 2
9 is a displacement member that moves the C0D28 by 1/2 pixel pitch in the direction perpendicular to the optical axis; 30 is the C0D2;
This is a COD driver that controls the drive of 8. It should be noted that the C0D 28 and the displacement member 29 are unitized as described later to constitute a solid-state m-image device.

Further, 31 is a signal processing circuit that processes a video signal imaged by the C0D 28 by a method described later, and 32 is an IC card that stores signal-processed digital image information.

Here, the displacement mechanism of the solid-state Wi image device will be explained using FIGS. 9, 10, and 11.

9 and 10 are a front view and a side view, respectively, of the displacement member 29 to which the C0D 28 is attached.

Moreover, FIG. 11 is a sectional view taken along the C--C line in FIG. 1.

In Figure 19, the displacement member 29 has a protrusion 29 at the center of the left side.
It is composed of a substrate 291 on which the projection 1a is formed and a displacement driving section 294 fixed to the projection 291a. Also,
The support member 281 of C0D28 is in the horizontal direction (arrow H in the figure).
direction) so as to be slidably attached to the substrate 291. That is, V-shaped bearing portions 281a, 281b and 2 are provided at both ends of the upper side and at the center of the lower side of the support member 281.
81C, and a nut portion 282a for screwing the flexible pressure contact pieces 283a, 283b, and 283C, respectively.
282b and 282C are formed, and the substrate 291
Shafts 292 and 292' are provided on the upper and lower sides, respectively. The support member 281 supports the bearing portion 28
1a and 281b and the pressure contact pieces 283a and 283b sandwich the shaft 292, and the bearing portion 28
1C and the pressure contact piece 283C, the axial direction of the shaft 292.292' is
That is, it is attached so as to be slidable in the direction of arrow H.

Further, as shown in FIG. 11, the displacement drive section 294 is configured to have a piezoelectric power inside a cylindrical container formed by fitting an outer frame 295 and an inner frame 296 having a hole 296b formed in the bottom surface, for example. It is constructed by enclosing an element 298 and a sliding member 297. That is, the sliding member 297 has a cylindrical portion 297
It has a structure in which five cylindrical pieces 297b are formed on the outside of the bottom surface of the inner frame 296, and the cylindrical part 297a has an outer diameter equal to the inner diameter of the inner frame 296 and the outer diameter of the groove. is between the hole 296b and the path. Further, the cylindrical portion 2
The open end of the inner frame 296 is folded back to form an abutting portion 297C for the open end 296a of the inner frame 296. Then, the piezoelectric element 298 is inserted into the cylindrical portion 297a of the sliding member 297, and the sliding member 297 is further inserted into the spring 299.
The five pieces 297b are inserted into the inner frame 296 so as to pass through the holes 296b through the holes 296b. As a result, the sliding member 297 is always urged toward the outer frame 295 by the spring 299, and the piezoelectric element 298 is fixed by the sliding member 297 and the outer frame 295. In addition,
The opening end 296a of the inner frame 296 and the contact portion 297c
In the initial state when no voltage is applied to the piezoelectric element 298, there is a distance of 1/2 pixel pitch of C0D28,
For example, a gap d of 5 μm is provided. Piezoelectric element 29
When a voltage is applied to the piezoelectric element 298 and the sliding member 297 is moved to the right by the displacement of the piezoelectric element 298, the contact portion 297C touches the opening end 296 at the point where the sliding member 297 moves by 1/2 pixel pitch.
a, and its movement is stopped, so the sliding member 29
7 moves exactly by 1/2 pixel pitch.

The displacement driving section 294 is fixed to the side surface of the protrusion 291a by screwing the bottom surface of the outer frame 295. On the other hand, the support member 281 is urged toward the displacement drive section 294 by a spring 293, and its side surface comes into contact with the tips of the five pieces 297b of the displacement drive section 294, thereby inhibiting the movement of the support member 281. has been done. Then, when a voltage is applied to the piezoelectric element 298, the sliding member 297 moves to the right by exactly 1/2 pixel pitch due to the elongation displacement of the piezoelectric element 298, as described above. also moves to the right by exactly 1/2 pixel pitch. This allows the C0D 28 to be accurately displaced by 1/2 pixel pitch. Furthermore, when the voltage application is stopped, the piezoelectric element 298 is reduced and displaced to its original state, so that the sliding material member 297 moves to the left by exactly 1/2 pixel pitch, and as a result, the support member 281 also moves accurately. , it moves to the left by 1/2 pixel pitch and returns to the initial state.

Returning to FIG. 1, the switches will be explained.

Switch SM is a main switch for starting the camera. The main switch SM is turned on when the photographing mode changeover switch 9 is slid to the rNORM, J or rCHARACT, J position. When the main switch SM is turned on, power is supplied from the power supply circuit 18 to each of the circuits. The switch S1 is a switch that is turned on when the release button 2 is pressed halfway, and starts preparations for photographing such as photometry and distance measurement. Switch S2 is turned on by fully pressing release button 2,
This is a switch that starts exposure.

The switch Sp is a switch that detects that the normal shooting mode is selected, and the shooting mode changeover switch 9 is set to r.
When set to NORM, J position, it becomes on state. The switch Sc is a switch that detects that the text shooting mode is selected, and is a switch that detects that the text shooting mode is selected.
When rCHARACT is set to J position, it becomes on state. The switch SNO is a switch that detects that the standard shooting mode is selected, and when the magnification changeover switch 10 is set to the rNORM or J position,
Turns on. The switch SUP is a switch that detects that the macro photography mode has been selected, and is turned on when the magnification changeover switch 10 is set to the rcLO8E UPJ position. The switch SFL is a switch corresponding to the light emission mode switching button 11, and is turned on when the forced light emission mode is selected by the button 11, and turned off when the light emission prohibition mode is selected. The switch SIc is a switch that detects the installed state of the IC card 32, and turns on when the IC card 32 is installed.

Note that the signals inputted to the CPU 17 by the switches described above become low signals in the on state, and become high signals in the off state.

FIG. 2 is a circuit diagram of the signal processing circuit 31. As shown in FIG.

The signal processing circuit 31 shown in the figure is composed of a processing block 33 that processes a video signal photographed in the normal photographing mode, and a processing block 34 that processes a video signal photographed in the character photographing mode. The switch 35 corresponds to the shooting mode changeover switch 9, and the common terminals a1 and a2 are connected to the G (green) signal output terminal and the R (red)/B (blue) signal output terminal of the C0D28, respectively. There is. Furthermore, when the normal shooting mode is selected, the common terminals a1 and a2 are connected to the terminals S, b2, respectively, and when the character shooting mode is selected, the common terminals a1 and a2 are connected to the terminals C, respectively.
I and c2.

In the processing block 33, the G analog video signal output from the C0D 28 is converted into, for example, an 8-bit digital video signal by the A/D converter 36a.
It is temporarily stored in the memory 37a. Further, the G digital video signal is subjected to white balance (WB) correction by a WB correction circuit 38a, and grade II (γ) correction is performed by a γ correction circuit 39a. On the other hand, the R/B analog video signal is converted into a digital video signal by the A/D converter 36t) and then temporarily stored in the memory 37b. 3
White balance (WB) correction is performed by 8b, and γ
After the correction circuit 39b performs gradation (γ) correction, the separation circuit 40 separates the signal into an R signal and eight signals. The signal-processed RlG and B signals are input to a luminance signal generation circuit 41 and a matrix circuit 42, the luminance signal generation circuit 41 generates a luminance signal (Y), and the matrix circuit 42 generates a color difference signal (Y). RY, B-Y) are generated. The luminance signal (Y) has its black level adjusted in a pedestal circuit 43, is further added with an NTSC synchronization signal in a synchronization signal addition circuit 44, and is then subjected to compression processing using, for example, an ADCT method in a compression circuit 45a. IC card 3
The image is recorded in the image memory within 2. On the other hand, the color difference signals (RY) and (B-Y) are subjected to the same compression processing as described above by compression circuits 45b and 45c, respectively, and are sent to the IC card 3.
The image is recorded in the image memory within 2. Note that the ADCT compression method is ADCT (Acjapt i veo+5
crete Co51ne Transform)
Image data is converted into data in the frequency domain from low frequency to high frequency using an orthogonal transformation called transformation, and for example, data of high frequency components is compressed by reducing the number of sampling bits. It is.

In the processing block 34, the G analog video signal output from the C0D 28 is converted into, for example, a 3-pit (8N) digital video signal by the A/D converter 47a, and is temporarily stored in the memory 48a or memory 48b. be remembered. As will be described later, the digital still camera according to the present invention is configured to perform two exposures in one photographing operation. In the character/shadow mode, the G digital video signal from the first exposure is stored in the memory 48a, and the G digital video signal from the second exposure is stored in the memory 48b. Furthermore, the R/B analog video signal output from the C0D28 is sent to the R/B separation circuit 4.
After being separated into R signal and 8 signals by 6, each A
The signal is converted into a digital video signal by /D converters 47a and 47C, and is temporarily stored in memory 48c or memory 48d. The R and B digital video signals from the first exposure are stored in the memory 48c, and the R and B digital video signals from the second exposure are stored in the memory 48c.
It is stored in d. Note that the A/D converters 47a to 47
Number of bits (number of gradations) of digital value converted by c
varies depending on the brightness of the subject, and is calculated and set by the CPU 17 from the results of preliminary photometry before photographing, as will be described later. Each of the RGB digital video signals is inputted to the slice circuit 49 after adding the first and second exposure data. Then, the slice circuit 49 slices each bit, and the run-length encoding circuit 50 encodes the signal, and then transfers it to the IC card 32 and stores it in the built-in image memory.

6 to 8 are schematic diagrams showing the internal structure of the digital still camera. FIG. 6 is a schematic front view, FIG. 7 is a schematic plan view, and FIG. 8 is a schematic side view.

In the internal structure of the digital still camera, a shutter 26 is disposed at a suitable position in the optical system constituting the photographing lens 6, and a close-up lens 51 for changing the focal length is disposed (see FIG. 8). Further, a mirror 2 including the above-mentioned motor drive circuit 27 adjacent to the photographing lens 6 is provided.
5. A drive mechanism 52 for the shutter 26 and close-up lens 51 is provided. Further, a control circuit board 53 in which a CPL 117 and various control circuits are installed is disposed at the rear of the drive mechanism 52, and a displacement member 29, the above-mentioned COD driver 30, a displacement control circuit for the displacement member 29, etc. are disposed at the rear of the drive mechanism 52. An imaging circuit 55 is provided which is combined with the incorporated m-image circuit board 54 to form a unit. In addition,
This imaging circuit 55 is arranged at a predetermined position where the ** surface of the CCD 2B is the imaging position of the photographic lens 6. A recording circuit board 57 incorporating the signal processing circuit 31 and the like is disposed along the back side of the camera body 1, sandwiching the mounting portion 56 of the IC card 32.

Further, a lamp 58 is disposed at a suitable position inside the floodlight window 7,
A photometric lens system 59 and a light receiving element 60 are disposed at a predetermined position inside the photometric window 8 . Furthermore, a xenon tube 62 integrated with a reflector 61 is disposed at a proper position inside the flash W, 5, and a main condenser 6 is disposed at a proper position below the xenon tube 62.
3 and a flash circuit board 64 are provided. A power battery B is housed at the bottom of the main body 1.

Next, the photographing operation of the digital still camera will be explained.

First, the main routine will be explained using the flowchart shown in FIG.

When the power supply battery B is inserted, a power-on reset is activated, and the CPLJ 17 clears the RAM, initializes each circuit block, flag, etc. (#1), and starts the operation of the following main routine.

First, it is determined whether the main switch SM is on or not (#2). If the main switch SN is off, the process moves to #19, and if the main capacitor 63 is being charged, the step-up is stopped. and return to #2. If the main switch SM is in the on state, the process moves to #3, and the main switch SM now wants to change from the off state to the on state.
It is determined whether the power is turned on) or whether the on state is maintained. If the main switch SM changes from the off state to the on state, the boost flag F1 is set to 1 to instruct the boosting (#4).
, if the on state is maintained, the process of #4 is not performed, and the IC card 3 is then turned on from the state of the switch Src.
It is determined whether or not 2 is attached (#5)
. If the IC card 32 is installed (switch Stc
is ON), and the corresponding switch S! It is determined whether c has changed from the off state to the on state (the IC card 32 has now been installed) or whether the on state has been maintained (the IC card 32 has already been installed) (#6 ), if the state changes from off to on, the boost flag F
If 1 is set to 1 (#7) and the on state is maintained, no special processing is performed and it is then determined whether there is memory capacity remaining in the inserted IC card 32. is carried out (#8). If there is memory capacity of the IC card 32 remaining, it is determined that photography is possible and the process moves to #9, and it is determined whether the switch S1 is on. If there is no memory capacity remaining, it is determined that photography is not possible and the process moves to #11. , the boost flag F1 is set to 0, and #12
to move to. If switch S1 is on in #9,
Furthermore, the CPU 17 detects that the switch S1 has changed from the off state to the on state (the release button 2 has now been fully pressed).
It is determined whether the switch is in the on state (al 0), or whether the on state is maintained (the half-pressed state of the release button 2 is maintained), and whether the switch S1 changes from the off state to the on state. For example, the process moves to the "Sl" routine (#20), which will be described later, and if the on state is maintained, the process moves to #12.

In #12, the state of the switch SNO (setting state of photographing magnification) is determined, and if the switch SNO is in the ON state It (standard photography), the photographing lens 6 is set in the standard state, and the switch SNO is in the OFF state Im ( macro photography), the photographing lens 6 is set to the macro photography state and the process moves to #15. Note that the photographing lens 6 can be switched to the macro photographing state by inserting the magnification switching close-up lens 51 onto the optical path. In #15, the state of the boost flag F1 is determined, and if O is set, #
19, the boosting operation is stopped and the process returns to #2. If the boost flag F1 is set to 1, CPL11
7 determines whether charging of the main capacitor 63 is completed (#16), and if charging is completed,
Since boosting is not necessary, the process moves to the above-mentioned #19, the boosting is stopped, and the process returns to #2. Further, if charging is not completed, boosting is started and time measurement by a boosting timer is started (#17). Subsequently, it is determined whether or not a predetermined boost time period has elapsed (#18), and if the predetermined time has not elapsed, the process returns to #2 and the operations from #2 to #16 are repeated. On the other hand, if charging is not completed within the predetermined boost time and a timeout occurs (YES in #18),
It is determined that the capacity of power supply battery B has decreased, and the photographing operation is prohibited.

Next, using the flowchart in FIG.
Explain the routine.

When entering the "Sl" routine, if the boosting operation is in progress, the boosting operation is temporarily stopped (#21), and the shooting mode set by the 1-shadow mode changeover switch 9 is determined (#21).
22>. Text shooting mode is set (switch Sc is ON)
If so, move to #51 (Figure 15), and proceed to #51~
Character photographing processing is performed in #66, and if the normal photographing mode is set (switch Sc is 0FF), the process moves to #23, and normal both photographing processes are performed in #23 to #50.

In the normal shooting mode, the distance measuring circuit 19 measures the subject distance, and the shooting lens 6 is adjusted to the focused state (#2
3). Subsequently, the photometry circuit 20 measures the brightness of the subject, and the CPU 17 determines whether or not a flash is necessary based on the subject distance and the measured value, and determines the Ffl when the flash fires.
i and the F value when the flash is not emitted are calculated (
#24).

Furthermore, the color temperature of the subject is measured by the AW8 circuit 23,
White balance (WB) adjustment processing is performed (#25
). Subsequently, the set state of the boost flag F1 is determined (
#26) If the boost flag is F1-1, it is further determined whether charging is completed (#27>. If charging is not completed, charging of the main capacitor 63 is started by the flash circuit 24. (#28).Next, it is determined whether charging is completed within a predetermined time, and during the charging operation, switches Sl5M and Sxc are turned off, and switch Sc is turned on. Confirmation of whether or not there is a change is performed sequentially (#28 to #3
3 loop). That is, it is confirmed whether the power is turned off, the photographing preparation operation is canceled, the photographing mode is switched from the normal photographing mode to the character layered mode, and the IC card is ejected.

During the charging operation, if any one of the switches S18M and SIC changes to the OFF state and the switch Sc changes to the ON state (#30, #31, #33
t1Jl) Su? 7rNO1 #32 (YES), #2
Return to , and perform the photographing operation described above again from the beginning. on the other hand,
During the charging operation, switches $1, SM, Sc and SIC
When charging is completed within the predetermined time without any change (YES in #29), charging of the main capacitor 63 is stopped (#35), the process returns to #23, and the above-mentioned distance measurement, photometry, etc. Processing takes place. Also, if charging is not completed within the specified time (YES in #34), power supply battery B
Shooting operation will be prohibited if it is determined that the capacity has decreased (#36
).

If the boost flag F1 is set to 0 in #26, or if charging is completed in #27, then it is determined whether the release switch S2 is turned on (#37). If the release switch S2 is in the off state (No in #37), the process moves to #47, and while the special function is on until the release switch S2 is in the on state, #47
~ Switch S1.8M%Sc and St described above in #50
The presence or absence of a change in c is confirmed. The relevant standby switch S
1. If there is a change in any one of the switches SM, Sc, and SIC (No in any step of #47, #48, or #50, YES in C49>, return to #2 and repeat the process described above from the beginning again. On the other hand, if the release switch S2 is turned on without any change in switches S1, SN, S, c, and SIC during the standby period (
YES at C37), the mirror 25 starts to move out of the optical path, and the shutter 26 starts opening (C38).
, #39), and further initialization of C0D28 is performed (C4
0). Then, when the mirror 29 is completely retracted out of the optical path and the shutter 26 is opened to the predetermined F value calculated in C25 (YES in C41 and C42), exposure in the normal shooting mode to be described later is performed. (C43) The predetermined F value is the Flashmatic F value calculated from the subject path distance and subject brightness when the flash is emitted, and is calculated from the subject brightness when the flash is not emitted. This is the F value.

Exposure in the normal photographing mode will now be explained according to the flowchart of "Exposure 1" in FIG. 16.

First, the total exposure time t corresponding to the F value calculated in C25
(seconds) and 11ic (seconds) at the displacement of C0D28 are compared (C71), and mt at full exposure is 1ic (seconds) at the displacement of C0D28.
If it is more than c (t≧jc), C72 to C86 described later
Exposure processing is performed according to the flow, and the total exposure time t is C
At displacement of 0D28 W! If it is less than itc (tku"c>
, Wk Exposure processing is performed according to the flow at C87 to C104 described below. Exposure processing will be explained separately for each case below.

(1) When t≧tc First, the full exposure tilt (seconds) and displacement time jc (seconds)
The time difference t1 (-i-tc) is calculated (C72)
Furthermore, a time tz (seconds) which is half of this time difference t1 is calculated (C73). Subsequently, at the same time as the charge accumulation of C0D28 is started, measurement of the time t2 is started (
C74, #75). Then, when the time t2 is counted down to 0 (YES in C76), the boost flag F
1 set state is determined (C77), and the boost flag F1 is set.
is set to 1 (flash emission), the flash is emitted (C78). Note that the amount of light emitted by the flash at this time is -, which is half of the guide numbers 〇 and No. Subsequently, measurement of the displacement time tc is started at the same time as the displacement of C0D28 is started (C79, #80
). If the boost flag F1 is set to O (flash does not emit) at C77, the process moves to C79 without emitting the built-in flash, and measurement of the displacement and displacement time tc of C0D28 is started. Then, when the displacement time tc has elapsed and the displacement of C0D28 is completed (YES at C81)
), the set state of the boost flag F1 is determined again (C8
2) If the boost flag F1 is set to 1, the flash is emitted at the same time as the time I! I! Measurement of t2 is started (C83, C84).

Note that the amount of light emitted by the flash at this time is also half the amount of guide numbers G and No, similar to the amount of light emitted at the first time.

On the other hand, if the boost flag F1 is set to 0 at C82, the process moves to C85 without emitting a flash, and measurement of time t2 is started.

Then, when the time 111t2 is counted down to O (YES in C85), the charge accumulation in the photosensitive section of the CCD 28 is stopped, and the accumulated charge is further transferred to the transfer section of the C0D28 (C86), and II output ends. Then, the process returns to C45 (C105).

FIG. 17 is a time chart showing the exposure process in case (1) above. In the figure, when switch S1 is turned on at point A and release switch S2 is turned on at point B, distance measurement and photometry processing are performed between points A and B, and focus adjustment and exposure time t are performed. An operation is performed. Further, retraction of the mirror 25 and opening of the shutter 26 are started from point B, and charge accumulation in the C0D 28 is started from point 0, where these operations are completed. Then, charge is accumulated in C0D28 during the exposure time at from point 0 to point E. on the other hand,
Displacement of C0D28 starts from point D, which is t2 (-(t-tc)/2) seconds after 0 point, and E after time tc seconds has elapsed.
The displacement of 1/2 pixel pitch is completed at the point. In addition, when emitting a flash, at the above-mentioned point and the above-mentioned point E, that is, immediately before the start of displacement of the COD 28 and after the displacement,
1/2 of the total amount of flash light is emitted.

Furthermore, since the aperture of the shutter 26 is set to an appropriate aperture value based on Flashmatic calculation, the total amount of light emitted by the flash is divided into two, and the total amount of light is emitted within the total exposure time. The exposure amount for the main subject will be appropriate even if the camera is set to

(2) When ic>j First, the time difference i1' (-t(-i)) between the displacement opening tc (seconds) and the total exposure time t(seconds) is calculated (#87
), furthermore, the time t3 (-t/2
> is calculated (#88). Next, the first charge accumulation starts in the photosensitive part of C0D28 (#89)
, the set state of the boost flag F1 is determined (#90)
, if the boost flag F1 is set to 1, a flash is emitted (#91). Note that the amount of light emitted by the flash at this time is half the amount of the guide number G, No. Subsequently, at the same time as the displacement of C0D28 is started, 1
Measurement of the second exposure time t3 is started (#92.#9
3). If the boost flag F1 is set to 1 in #90, the process moves to #92 without emitting a flash, and measurement of the displacement of C0D28 and 1mt:+ at exposure is started. Then, when the exposure time t3 is counted down to O (YES in #94), charge accumulation in the photosensitive part of C0D28 is stopped, and the first accumulated charge is reduced to C0D2.
The data is transferred to the transfer unit No. 8 (#95). Next, C0D2
After the overflow drain (hereinafter referred to as OFD) of No. 8 is opened and unnecessary charges generated in the photosensitive area are discharged to the OFD (#96), measurement of the time difference t1' is started (#96).
97). When the time difference t1' is counted down to 0 (YES in #98), the OFD is closed and the CO
D The second charge accumulation on the photosensitive part of 28 starts (
#99). Next, the set state of the boost flag F1 is determined (#100), and if the boost flag F1 is set to 1, the flash is emitted and f! [
Measurement of lt3 is started (#101, #102). Note that the amount of light emitted by the flash at this time is also half the amount of guide numbers G and No, similar to the amount of light emitted at the first time. On the other hand, if the boost flag F1 is set to O in #100, the process moves to #102 without emitting a flash, and measurement of the exposure time t3 is started. Then, when flflt3 is counted down to O during the exposure (#
103: YES), the charge accumulation in the photosensitive part of the C0D28 is stopped, and the accumulated charge is further transferred to the transfer part of the C0D28 (#104), and the exposure is completed and the process returns to #44 (#105). Note that at this time, the charge in the transfer section is 1
The first accumulated charge and the second accumulated charge are mixed, resulting in a total accumulated charge amount of @1 (-2Xtz) at the time of full exposure.

FIG. 18 is a time chart showing the exposure process in case (2) above. In the figure, the displacement of C0D 28 is started from point 0, where the mirror 25 has been retracted and the shutter 26 has been opened, and the displacement is completed at one point after the displacement time tc has elapsed. C0D28 is laterally displaced by 1/2 pixel pitch after one point. Also, the photosensitive part of the CCD 28 is 1
The first charge accumulation is performed, and the first accumulated charge is transferred to the transfer section of the C0D 28 at the point G. Also, from point G to t1
' Time t3 (=t/2> from point H to point 1 that has passed)
The second charge is accumulated in the photosensitive part of the CCD 28 for only a moment, and at this point, the second accumulated charge is transferred to the transfer section of the CCD 28, and the first and second accumulated charges are mixed in the transfer section. . In addition, the question from point G to point H is OF of C0D28.
D is open, and no charge is accumulated in the photosensitive portion of C0D28. Also, when firing a flash, at the 0 point and H point, which are the first and second exposure start points,
1/2 of the total amount of flash light is emitted.

In this case as well, the total amount of light is emitted within the total exposure time t (-2 Even if this is done, the exposure amount of the main subject will be appropriate as in case (1).

Note that in the normal photographing mode, when the C0D 28 is not displaced, exposure is performed according to the flowchart of [N output 1aJ] in FIG.

First, charge accumulation of C0D28 is started (#161),
Subsequently, the set state of the boost flag F1 is determined (#1
62). If the boost flag F1 is set to O (flash not emitted), a down count of the exposure time t is started (#163), and at the same time, a timer for measuring the camera shake limit time tK is started (#164). This camera shake limit time tK is! This indicates the maximum exposure time for shadows to be properly produced without camera shake, and is a problem when a relatively long exposure time without flash emission is required.

And at the time of said exposure I! It is determined whether the camera shake limit time tK is reached before t becomes 0 (#165.#1
66), if the camera shake limit time tK is not reached within the exposure time lit (YES in #165>, charge accumulation is stopped after the exposure time l[lt has elapsed (#168), and the exposure time il
If the camera shake limit time 1K is reached within t (YES in #166), the shutter is forcibly closed (#167) and charge accumulation is stopped (#168).

On the other hand, if the boost flag F1 is set to 1 in #162 (flash emission), the timer that measures the timing of flash emission starts at the same time as the down count of at at the time of exposure starts (#169) (#170). ). This flash emission is performed at a timing after a predetermined period of time has elapsed from the start of exposure of the C0D28. Then, by the time the exposure time t reaches O, it is determined whether the flash emission timing has arrived (#171,
#172) If the timing for flash emission does not come within the exposure time (YES in #171), the flash will not be emitted, and charge accumulation will be stopped after the exposure time t has elapsed (#174), and within the exposure 1yst. When the timing to emit the flash comes (YES in #172), the flash is emitted (#173), and charge accumulation is stopped after the exposure time @1 has elapsed (#174).

Returning to FIG. 14, when the exposure is completed, closing of the open shutter 26 is started (#45), and at the same time, C0
The accumulated charges (video signal charges) in the transfer section of D28 are transferred to the signal processing circuit 31 (#46). Subsequently, the video signal is subjected to predetermined signal processing in a signal processing circuit 31, converted into a luminance signal (Y) and color difference signals (RY, B-Y), and then stored in an IC card 32. Ru.

Next, the text shooting mode will be explained. When the character photographing mode is set in #20, the lamp 58 is turned on by the light projecting circuit 24, and the lamp light is irradiated onto the character to be photographed (FIG. 15, #51).

The irradiation range of the lamp light corresponds to the shooting range, and this allows the photographer to know the shooting angle of view.

Further, since the lamp light is evenly applied to the entire character to be photographed, the brightness of the photographed object can be made uniform.

Subsequently, the distance measuring circuit 19 measures the object distance, and the focal point of the photographing lens 6 is adjusted based on the object distance, and the photometering circuit 20 measures the object brightness, and the exposure time mt is set based on the measurement result. (#52.#53
). Next, it is determined whether the release switch S2 is turned on (#54), and if the release switch S2 is off (No in #54), the process moves to #62 and waits until it turns on. do. During standby, it is checked whether the switches S1.5M5Sc and Src described above are turned off (#62 to #65), and during the standby, any one of the switches S1 SM, SC and SIC is turned off. When the state changes (#62 to #65
(No in any step), the lamp 58 is turned off by the light projection circuit 27 (#66), and then the process returns to #2. On the other hand, when the release switch S2 is turned on without changing any of the switches S+, SM, SC, and Stc (#
54: YES), the mirror 25 starts to be moved out of the optical path (mirror up) (#55), and then the shutter 26 starts to open (#56). Also, COD driver 3
0 starts the initialization of C0D28 (#57).

Next, when the mirror 25 is completely retracted out of the optical path and the shutter 26 is opened to the predetermined F value calculated in #23 (YES in #58 and #59), the text shooting mode described later is started. Exposure is performed (#60), and when the exposure is completed, the lamp 7 is turned off by the light projection circuit 27 (#61>
, return to #2.

Next, exposure in the character photographing mode will be explained according to the flowchart of FIG. 20.

First, C for the exposure time t determined by photometry in #53.
Pre-order on CD28! Exposure is performed, and the threshold level of the gradation level is determined from the exposure result (#111
). In other words, A from the brightness signal level at which preliminary exposure was performed.
The gradation level of /D converters 47a to 47c is determined. Subsequently, the shutter 26 is opened and the first exposure is started (#112). Then, when the exposure time @t has elapsed, the charges accumulated in the photosensitive part of C0D28 are field shifted to the transfer part (#113), and at the same time
The FD is opened, charge accumulation in the photosensitive area is prohibited, and the first exposure is completed (#114). Next, C0D28
The displacement of the shutter 26 is started (#115), and the closing of the shutter 26 is also started (#116). At this time, as described above, the amount of closing of the aperture 65 due to the closing operation of the shutter 26 is monitored (#117), and the shutter 2 is moved until the amount of exposure by the shutter 26 becomes the same as the amount of exposure for the first time.
6 is occluded (YES in #117), the OFD of the CCD 28 is closed and the second exposure is started (#11
8). Then, when the shutter 26 is completely closed and the second exposure is completed (#119), the accumulated charge (first image data) from the first exposure held in the transfer section of the C0D 28 is transferred to the signal processing circuit 31. It is compared to (#120
), then the accumulated charge (second image data) accumulated in the photosensitive section of the C0D 28 due to the second exposure is read out to the signal processing circuit 31 via the transfer section (#121
>. In the signal processing circuit 31, an A/D converter 47a
-47C, the reference voltage and conversion voltage range are set according to the gradation level determined in #111. For example, when eight gradation levels are set, the G signal of the first image data is converted into a 3-bit digital video signal by the A/D converter 47a, and then temporarily stored in the memory 48a. Further, the first II image data R/B signal is separated into an R signal and a B signal by an R/B separation circuit 46, and each is converted into a 3-bit digital video signal by A/D converters 47b and 47c. After that, it is temporarily stored in the memory 48C. Similar A/D conversion processing is performed on the second image data, and the G digital video signal is stored in the memory 481), and the R and B digital video signals are stored in the memory 48d. Next, the first and second of R
The digital video signals related to the jll data are combined and input to the slicing circuit 49, and after the combined data is sliced for each bit, run-length encoding is performed in the encoding circuit 50. Further, similar processing is performed on digital video signals related to G and B first and second image data. The run-length encoded digital video signal is then stored in the IC card 32 (
#122).

FIG. 21 is a time chart showing the exposure processing in the text photographing mode. In the figure, the predetermined exposure time t is measured from the 0 point at which the mirror 25 has been retracted and the shutter 26 has been opened. Exposure is performed and the gradation level of A/D conversion is determined. Next, after preliminary exposure, C0D2 from 0 point
The first charge accumulation starts in the photosensitive area of 8, and the front &! Ends at the point where @1 has elapsed during exposure. After the first exposure is completed, the displacement of the C0D 28 is started from point K, and at the point where the displacement ends, closing of the shutter 26 is started.

Then, at point M, where the aperture 66 is closed by a predetermined amount, the OFD is closed, and the second charge accumulation is started.

The charge accumulation continues until point N, at which the shutter 26 is completely closed.

Next, the exposure operation in the character photographing mode when FIT-COD is used as the II image element will be explained according to the flowchart of FIG. 22. The flowchart in FIG. 22 replaces the flowcharts #53 to #59 in FIG. 15, so the operation after moving from #52 in the figure to #131 in FIG. 22 will be described.

After photometry is carried out in #52 and the exposure time t is set based on the photometry result, it is determined whether the release switch S2 is in the on state (#131), and if it is in the off state, it is determined in #62.
(see Figure 15), if it is on, C0D
28 initialization is performed (#132). Next, the mirror 25 is moved out of the optical path (mirror up) and the shutter 26 is moved.
opening is started (#133). And mirror 25
completely retreats out of the optical path and the shutter 26 opens to the predetermined F value calculated in #23 (YES in #134),
C0D2 for the exposure time t determined by photometry in #53.
8, preliminary exposure is performed (#135), and the gradation level is determined from the exposure result (#136). Next, C0D2
Unnecessary charges accumulated in the photosensitive parts of the odd-numbered lines of 8 are discharged to the transfer part, and the first exposure is started for the odd-numbered lines (#137). Also, after a predetermined time delay, C0D2
Unnecessary charges accumulated in the photosensitive parts of the even numbered lines of 8 are discharged to the transfer part, and the first exposure is started for the even numbered lines (#138). Subsequently, after an exposure time has elapsed since the start of exposure of the odd-numbered lines, the charges accumulated in the photosensitive parts of the odd-numbered lines are field-shifted to the transfer part, and the first exposure of the odd-numbered lines is completed (#139). Subsequently, the odd-numbered line video signals transferred to the transfer section are read out to the signal processing circuit 31, and after being A/D converted at a predetermined gradation level as explained in the first embodiment, they are stored in the memory 48a and 4
8c (#140).

Subsequently, after the exposure time has elapsed from the start of exposure of the even-numbered lines, the charges accumulated in the even-numbered lines are field-shifted to the transfer section, and the first exposure of the even-numbered lines is completed (#141). The even-numbered line video signals transferred to the transfer unit are also read out to the signal processing circuit 31 in the same way as the odd-numbered line video signals, and after A/D conversion at a predetermined gradation level, are stored in the memories 48a and 48C. be done. When the first exposure is completed, the OFD of C0D28 is opened and charge accumulation in the photosensitive area is prohibited (#142).
. Subsequently, displacement of C0D28 is started (#143),
Further, closing of the shutter 26 is started (#144). At this time, as described above, the amount of closing of the aperture 65 due to the closing operation of the shutter 26 is monitored (#145),
When the shutter 26 is closed to the position where the exposure amount by the shutter 26 is the same as the first exposure amount (Y in #145)
ES), the OFD of C0D28 is closed and the second exposure is started (#146). The second exposure operation is #14
6 to #150, which are the same as steps #118 to #122 (see FIG. 20) described in the first embodiment, so their explanation will be omitted.

FIG. 23 is a time chart showing the exposure operation in the character photographing mode when the FIT-COD is used.

In the figure, preliminary exposure is performed for an exposure time t from the 0 point at which the mirror 25 has been raised and the shutter 26 has been opened, and the level of each gradation is set from the preliminary exposure result. Then, the first exposure is performed for the odd numbered line of the photosensitive area of C0D28 from the 0 point after the preliminary exposure for the exposure time t, and the first exposure is performed for the even numbered line of the photosensitive area of C0D28 from the point P for the exposure time of 1t. The second exposure is done. Then, at point R, where the first exposure has finished, C0
The OFD of D28 is opened, charge accumulation in the photosensitive portion is prohibited, and displacement of the C0D28 is started.

Closing of the shutter 26 is started at the 8 points where the displacement of the C0D 28 ends, and at the lower point where the aperture 66 is closed by a predetermined amount, the OFD is closed and the second charge accumulation is started. The charge accumulation is then carried out until the 0 point at which the shutter 26 is completely closed.

Incidentally, in the above embodiment, an optical low-pass filter is not used even in the normal shooting mode, but a low-pass filter may be used in the normal shooting mode. FIG. 24 is a configuration diagram showing one embodiment thereof. In this figure, the same members as in FIG. 1 are given the same numbers.

70 is a low pass filter (hereinafter referred to as LPF), 71
is a low pass filter (LPF) retracting means for retracting the LPF 70 from the optical path. In the figure, the LPF 70 is provided so as to be retractable in the darkness between the photographing lens 6 and the C0D 28. When the switch Sp is turned on and the normal shooting mode is selected, the CPU 17 activates the LPF retraction means 71.
A control signal is sent to the LPF 70, and the LPF 70 is placed on the optical path.

As a result, in the normal shooting mode, high frequency components are cut, making it impossible to achieve high resolution. On the other hand, when the switch Sc is turned on and the character photographing mode is selected, the CPU 17 sends a control signal to the LPF retracting means 71 to retract the LPF 70 from the optical path.

As a result, in the character photographing mode, there is no reduction in resolution due to the LPF 70, so high resolution can be achieved.

In the above embodiment, a piezoelectric element was used as a means for displacing the C0D28, but by displacing an optical prism and a horizontal transmission plate on the optical path, the C0D
The same effect as displacing 28 may be obtained.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to switch between the normal shooting mode and the high-resolution mode, so that the shooting mode can be used depending on the purpose of shooting, such as when giving priority to high resolution and when giving priority to release time lag. Suitable photography can be performed in either case.

[Brief explanation of the drawing]

FIG. 1 is a system configuration diagram of an actual example of a digital still camera according to the present invention, FIG. 2 is a circuit configuration diagram of a signal processing circuit, FIG. 3 is a front view of the digital still camera, and FIG. 4 is a diagram of the digital still camera. 5 is a side view of the digital still camera; FIG. 6 is a schematic front view showing the internal structure of the still camera; FIG. 7 is a schematic plan view showing the internal structure of the still camera. 8 is a schematic side view showing the internal structure of the digital still camera, FIG. 9 is a front view of the COD displacement member, and FIG. 10 is a schematic side view showing the internal structure of the digital still camera.
FIG. 11 is a side view of the OD displacement member, FIG. 11 is a reduced cross-sectional view of FIG. , FIG. 14 is a flowchart of the "Sl" subroutine, FIG. 15 is a flowchart showing the shooting operation in the text shooting mode, and FIG. 16 is a flowchart of the "Exposure 1J subroutine" in the normal shooting mode.
The figure is a time chart showing the exposure operation when the exposure time is longer than the COD displacement time in the normal shooting mode.
Figure 8 is a time chart showing the exposure operation when the exposure time is shorter than the CCD displacement time in the normal shooting mode.
FIG. 19 is a flowchart of the [ll output 1aJ subroutine in the normal shooting mode, FIG. 20 is a flowchart of the "exposure 2" subroutine in the text shooting mode, and FIG. 21 is a time chart showing the exposure operation in the text shooting mode. The figure is a flowchart according to the second embodiment of the exposure operation in the text shooting mode, FIG. 23 is a time chart according to the second embodiment of the exposure operation in the text shooting mode, and FIG. 24 is a flowchart according to the second embodiment of the exposure operation in the text shooting mode. FIG. 1 is a configuration diagram of main parts of a digital still camera. 1...Camera body, 2...Release button, 3...
・AWB window, 4... Finder, 5... Flash window, 6... Shooting lens, 7... Light emitter window, 8... Metering window, 9... Power switch and shooting mode selector switch , 10... Shooting magnification switch, 11... Flash forced firing/flash inhibition button, 13... Display section,
15...IC card insertion slot, 17...CPU, 18
... Power supply circuit, 19... Distance measuring circuit, 20... Photometering circuit, 21... Flash circuit, 22... Display circuit, 23... AWB circuit, 24... Light emitter circuit, 25・
...Mirror, 26...Shutter, 26a, 26b...
- Shaft curtain, 27... Motor drive circuit, 28...
CCD, 29...Displacement member, 3o...COD driver, 31...Signal processing circuit, 32...IC card,
46-R/B separation circuit, 47a-47C...A/D
Converter, 488-48 (j... memory, 49... slice circuit, 50... run length encoding circuit, 58
... Lamp, 61 ... Reflector, 62 ... Xenon tube, 63 ... Main condenser, 65 ... Hole, 66
... Avachia-67... Photo Intergram Pig,
70...Low pass filter (LPF), 71...Low pass filter retraction means, 281...CCD support member, 294...Displacement drive unit, 298...Piezoelectric element, S
M, Sl. S2, Sp, SC, SNO, Sup, SFL. src...switch

Claims (1)

[Claims] 1. In a digital still camera that performs predetermined exposure using a solid-state image sensor in a normal shooting mode, a switching means for switching between the normal shooting mode and a high-resolution mode, and a switching means for switching the solid-state image sensor by 1/2 when in the high-resolution mode. A digital still camera comprising: a displacement means for performing parallel movement by a pixel pitch; and an exposure control means for performing the predetermined exposure before and after the displacement of the solid-state image sensor in high-resolution mode photography.